Lapping machine



March 221, 1949. P. J. SOMMER, JR 2,465,178

d LAPPING MAGHINE Filed sept. 2o, 194e `2 sheets-sheet 1' m/ENToR. P@Zefjnzmer J?, By

March y22, 1949. P. J. SOMMER, JR 2,465,178

I LAPPING MACHINE File d Sept. 20, 1946 2 Sheets-Sheet 2 MMI l ImiIl l A INVENToR.

' Pe/efdonmer J/r,

.BY A WwW/W Patented Mar. 22, 1949 LAPPING MACHINE Peter J. Sommer, Jr., Chicago, lill., assignor to Size Control Company, Chicago, lill., a copartnership Application September 20, 1946, Serial No. .698,115

(Cl. l-88) 3 Claims.

This invention relates to improvements in. precision machine tools. More particularly it pertains to a centerless lapping machine for precision finishing of cylindrical work pieces by means of two rollers each traveling in the same direction, the cylindrical surfaces of each roller being so spaced apart that they simultaneously support as Well as lap finish such work pieces therebetween, and the provision of such a machine is a principal object of the invention.

More specifically, an object of the invention is to provide a centerless lapping machine for precision finishing of cylindrical work pieces in which two lap cylinder rollers are utilized by being mounted upon rotatable shafts, the rollers having their cylindrical surfaces adjustably disposed and relatively movable with respect to each other, one of the rollers being of greater diameter than the other, and rotatable means connected to the shafts to drive the rollers at different rates of speed and in the same direction, the rollers being so spaced that they will simultaneously support as well as lap finish cylindrical work pieces placed between them.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts, which will be exemplified in the construction hereinafter set forth and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

Fig. 1 is a transverse elevational view illustrating a preferred embodiment of the invention;

Fig. 2 is a top plan view of the lapping rollers; and

Fig. 3 is a rear view showing the arrangement of the driving mechanism for the lapping rollers.

Referring more particularly to the drawings, there is shown generally at l0 a centerless grinding apparatus mounted within a safety cabinet indicated generally at II.

Two lapping cylinder rollers I2 and I3, preferably of unequal diameter are mounted upon rotatable shafts Ill, Inl. These rollers have their cylindrical surfaces adjustably disposed with respect to each other. That is, the shaft to which the roller i 2 is connected is mounted in rotatable position, whereas the shaft and journal bearing members for holding the roller I3 iand I3.

are movable toward and away from the roller I2 by means of, for example, a screw arrangement such as that depicted at l5. These two rollers are mounted within the cabinet i i on a platform .I6 immediately beneath a top cover member II of the cabinet I I. The rollers are exposed in such a manner that only their operating surfaces project above the top of the cover member. Adjacent each end of each roller there is a well I8 in the cover member for ready removal of a work piece IS as will more fully appear hereinafter. The cabinet I I encloses the remainder of the apparatus in such a manner as to provide safety in operation against accidents.

On a base platform 2li in the bottom of the cabinet II there is utilized a motor 2l for actuating the lapping rollers I2 and i3. Preferably,

this motor drives a belt 22 which in turn drives a pulley 23 secured to a shaft 24 mounted in a bearing 25 carried by an intermediate platform 26 in the cabinet II.

Disposed in parallel relationship to the shaft 24 is a countershaft 2l, mounted in a bearing 28 on the platform 26 and underlying the rollers I2 The countershaft 2l is driven from a pulley 2Q on the shaft 24. A belt 3U passes around the pulley 23 to a pulley 3i which in turn is secured to the countershaft 2l.

Also mounted on the countershaft 2l is a large pulley 32 as well as a smaller pulley 33. By means of a belt 34 the larger pulley 32 actuates a pulley 35 connected to the shaft Ill carrying the lap roller I2. The smaller pulley 33, by means of a belt 365, actuates a pulley 3l secured to the shaft I4 carrying the lap roller I3. By this arrangement both of the lap rollers are actuated at dierent rates of speed and in the same direction.

It will be observed that all of the bearings are resiliently mounted, for example, on rubber pads. This, in conjunction with the driving belts, eliminates chattering and obtains smooth surfaces on work pieces to be lap finished, eliminating chatter marks therefrom.

The means for adjusting the movement of the smaller diameter lap roller I3 Should be such that the space between its surface and the surface of the larger lap roller can be adjusted as desired. That is, it may be desirable to have the spacing at one end slightly greater than at the other end between the surfaces so that a work piece I9 (Fig. 2) can be moved in either direction from one end to the other and readily picked from between the operational surfaces as it reaches the well in the top cover of the cabinet II' adjacent the ends of each of the lap rollers I2 and I3. As illustrated in Fig-s. 1 and 2 the adjusting screws I5 may be rotatably supported in angle brackets 38 which are secured on the platform I6 immediately in front of the bearing supports 39. The screws I5 have their ends in threaded engagement with the bearing supports 38 and the bearing supports 39 are in sliding dovetail engagement with guide members 492. There is sucient play in the bearings' andl the sliding bearing supports to permit the slight angular movement of the shafts required for ad justing the rolls I2 and I3 as described.

It should be noted that it is within the contemplation of the invention tot-utilize the foregoing machine to lap grind othergages such as the interior surfaces of ring gages as well as thread gages and the like.

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof; it is intended@ thaty alli matter containedI in the above description or shown in the accompanying drawing shall be interpreted as illustrativerand not-in limiting sense.

It is also to be understoodthat the following' claims are intended to: coverall" of the generic and specic features of' the invention herein described, andi all statements of the scope ofL theVl invention which, asa matter"of'l'anguage, might be saidto fall therebetween.

Having described my invention what I claim as new and desire to secure byflettersy Patent' is 1. In a centerless lapping machine; forA preci'sion nishing of cylindricalf work pieces, the

improvement comprisingtwoflap cylinder rollers-v of unequal'- diameter each'l mounte'd upon shafts,

which rollershave their cylindrical surfacesladf jatently' disposed withrespectV` t'o' eacl'l` other, vthe larger ofl said rollersfllavingf its-sl`1aft journaledv in fixed position and the smaller of" said rollershaving its shaft journaledv in movable bearings, said bearings being adaptedl toV beA adjusted; toward'and-away from said larger rolleigrot'atable means connected to saidishafts to'drive 'sai-dirollers at different rates of speed-and'in the same direction, said rollers beingv so spaced? that they will simultaneously support as well as'lap finish'A said cylindrical work pieces therebetween, and said smaller roller' being angularlyV adjustable with respect to saidlarger roller so thatthelspa'cebetween both cylindricallsurfac'es is' such that-f a rotating work piece will be carriedI along saidA cylindrical surfaces-'from one endof-t eachI rollerto the other end thereof.

2. In a centerless lapping machine, for precision nishing of cylindrical work pieces, the improvement comprising two lap cylinder rollers each mounted upon rotatable shafts, which rollers have their cylindrical surfaces adjacently disposed and which rollers are relatively spaceable with respect to each other, one of said rollers being` of; greater diameter than the other, and rotatable means, including' a driven countershaft carrying two pulleys of unequal diameter, the larger of said pulleys being connected to the shaft carrying the lap roller of greater diameter by means of a belt to rotate the same, and the -smaller of said pulleys being connected to the lap roller of smaller diameter by means of a belt to rotate the same, both of said rollers being actuated. at different rates of speed and in the same direction, said rollers being so spaced that they will simultaneously support as well as lap nish said cylindrical work pieces therebetween.

3. In a centerless lapping machine, for precision nishing of cylindrical work pieces, the improvement comprising two lap cylinder rollers each mounted upon rotatable shafts, which rollers have their cylindrical surfaces adjacently disposed and which rollers are relatively spaceable with respect to each other, one of said rollers being of greater diameter than the other, rotatable means connected to said shafts to drive said rollers at, diierent rates of speed and in the same direction, said rollers being so spaced that they will simultaneously supportas well' as lap iinish said cylindrical` work pieces therebetween, and all of said rotating parts being resiliently mounted to eliminate vibration, thereby inhibiting the imparting of chatter marks to said work pieces.

PETER J. SOMMER, JR.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,062,803 Benedek Dec. l, 1936 FOREIGN PATENTS Number Country' Date 152,632 Great Britain May 18, 1920 459,551 Great Britain Jan. l1, 1937 OTHER REFERENCES Scientic American, March 1946, page 132, article entitled, Pin Lapping. 

